Dr. Brown's BPA Free Polypropylene 8 oz. Baby Bottles are our favorite baby bottle.  We have used them exclusively with our daughter and we have had little to no problem with spitting up, excessive gas or anything of that nature.  The design really does seem to eliminate the build up of air bubbles and we can really tell a difference between these bottles and the bottles we used with our boys.  We feel relieved to be able to feed our daughter with a BPA free bottle to help us to give her the healthiest start possible.  We wish these had been available when our sons were on the bottle.  Although...